There is already known from U.S. Pat. No. 3,043,913 of the applicant an apparatus specially conceived for the rehabilitation of the voice. This apparatus operates on the principle of the reaction between hearing and speaking discovered by the applicant.
Following research into the role of the internal ear on the general comportment of a human being has revealed its major role with regard to the activation of the brain considered as comprising the entire nervous system. In fact, the nervous system only functions under the condition that a permanent activation is effected. This activation is realized by the sensitive peripheral mechanism and more particularly by the internal ear which in some way serves the role of a dynamo recharging a central battery constituted by the central gray matter which in turn distributes the energy to the entire nervous system. If the permanent charge of the brain is not effected in satisfactory manner, this has the result, for the person in question, of a disturbance of the proper operation of the central mechanisms with regard to memory, concentration, activity of the human being in his integration of written and spoken language etc. This adverse operation can be translated by more or less serious difficulties such as loss of memory and concentration, depression, language difficulties leading to autism, stuttering, dyslexia, poor ability with foreign languages up to simple difficulties of the voice and also psychological and even psychiatric difficulties.